In hydraulic fracturing operations, removing the hydaulic fracturing fluids from subterranean hydrocarbon-bearing geological formations (the wellbore) and minimizing damage to the subterranean hydrocarbon-bearing geological formations are of utmost importance. Flowback aids are increasingly being used in the industry in order to enhance penetration and clean-up of hydraulic fracturing fluids, lower the surface tension of the treating fluid, and increase the contact angle of both water and hydrocarbons on treated mineral surfaces in subterranean hydrocarbon-bearing geological formations, which in turn are allowing for higher fluid return and hydrocarbon production.
Between about 50% to 90% of introduced stimulation fluids injected into wellbores during hydraulic fracturing operations may remain in the subterranean hydrocarbon-bearing geological formations. The trapped introduced stimulation fluids decrease well productivity by effectively lowering the available cross-sectional area available for fluid flow, including that of the hydrocarbons within the subterranean hydrocarbon-bearing geological formations.
Many flow-back aids or stimulation fluids have been developed to increase subterranean formation permeability, thereby enhancing fluid flow through fractured subterranean hydrocarbon-bearing geological formations. The enhanced fluid flow resulting from properly-deployed flow-back aids (or stimulation fluids) reduces potential damage from phase trapping, and the enhanced fluid flow increases the recovery of introduced stimulation fluids and hydrocarbons within the subterranean hydrocarbon-bearing geological formations.
Flow-back aid (or stimulation fluids) formulations typically contain solvents, for example, oils such as hydrocarbons, terpenes, esters, and surfactants and co-surfactants that are in solution or suspended in a microemulsion (see e.g., U.S. Pat. Nos. 8,091,646; 7,998,911; 7,989,404; 7,960,314; 7,893,010; 7,380,606; and 9,200,192; and U.S. Patent Publication Nos. 2011/0021386; 2009/0281004; 2008/0287324, 2012/0270758; 2013/0261033; and non-U.S. Patents and Publications; CA 2,864,308; and WO 2016/105395).